POSEIDON Examples

Policy-making with POSEIDON

• Understanding incentives
• Controlling incentives
• Improving Policy

Nudging targets

• 200 Fishers
• 2 Species of fish:
  • Expensive Blue
  • Cheap Red
• Selective Gear

No policy

Policy

• Problem:
  • Expensive stock being depleted
  • Long term loss of profitability
• Constraints:
  • Cannot enforce gear switch
  • Cannot remove fishers
• Question:
  • Can we tax blue or subsidize red to maximize long term profits?

Model for scenario evaluation

• Ban blue landings when stock below a threshold

Model for optimization

• Find % tax on blue to maximize 30-years profits

Fine-tuning ways and means

• New Objective:
  • Need to land approximately 600 blue fish a day
• Problem:
  • Fixed tax will not work
• Question:
  • Can we adjust incentives depending on landings?

Difficult Problem

Complicated Solutions

Complicated Solutions 2

Winners and Losers

• One species of fish
• Two kinds of fishers:
  • Large Commercial Vessels
  • Small Fishing Boats
• Problem:
  • Overfishing

Winners and Losers (2)

Policy

• Problem:
  • Overfishing
  • Low profits for small fishermen
• Constraints:
  • Cannot regulate small boats
  • Cannot enforce quotas
  • Can only implement one MPA
• Question:
  • Where should we place this MPA?
  • Who wins and who loses?

Pareto Front

Leftmost Solution

Rightmost Solution

Buyouts

• New Constraint:
  • We cannot impose any MPA
  • We can only buy large vessels out of the market
• Question:
  • How many should we buy?

Scenario Evaluation